House Extensions Kingston
Single storey rear and double storey extensions in Kingston upon Thames, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
Kingston upon Thames has the plots that suit good extensions, from the side returns and rear closet wings of its Victorian and Edwardian terraces to the generous gardens of the interwar semis and larger houses towards Coombe and Richmond Park. GS Renovation builds single and double storey extensions across KT1 to KT6 and KT9, drawing on our founder's 30+ years on the tools.
In Kingston upon Thames, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Kingston upon Thames: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Kingston upon Thames
Kingston upon Thames range: choose above
Side return extensions across Kingston terraces
The side return is the strip of ground beside the rear closet wing on a Kingston terrace, usually wasted on a narrow passage. Filling it in widens a cramped galley kitchen into a bright kitchen-diner running the full width of the house. We dig new foundations to suit the ground, tie into the existing wall, install steel to carry the opened structure and add a glazed roof or rooflights to pull daylight deep into the plan.
Whether your extension is permitted development or needs a full planning application depends on the property. Many single storey rear and side-return builds in KT1, KT2 and KT3 fall within permitted development, but side-return builds in a conservation area, or homes already extended, usually need permission from Kingston Council. We advise on which route applies, coordinate the drawings with your designer, give you what you need to serve party wall notices where a boundary wall is shared, and build the whole thing to building regulations.
Housing in Kingston upon Thames
Of the 70,440 homes the valuation list records in Kingston upon Thames, 21% were built before 1919, 34% between the wars and 45% since 1945; 42% are flats and 59% are houses. 26% of homes here are semi-detached; a rear extension on a semi in Kingston upon Thames digs beside the attached neighbour, so one party wall notice is usual.
Kingston upon Thames design limits on single storey rear extensions
Kingston's Residential Design SPD says single storey rear extensions should generally not exceed 3 to 3.5m in depth, and sets heights by roof type: 3m for a flat roof, 3.3m for a parapet roof and 4m for a pitched roof. Where an extension in Kingston upon Thames goes to a planning application, those figures decide the roof before the kitchen layout. A parapet buys height but puts the gutter behind the wall line, so the structural engineer we appoint details a box gutter and the steel under it. A pitched roof gains height at the ridge but has the least at the eaves, beside the neighbour.
The same SPD says that in all cases at least 50% of the rear garden should remain when a single storey rear extension is added. On a short garden that can bind before the depth limit does, so we measure the garden first and check both limits against the plan. 37% of homes in Kingston upon Thames are semi-detached or detached, and on a semi the extension runs beside the attached neighbour, which normally brings a party wall notice for the new foundations. Fixing the depth early means that notice describes the building you will actually build.
Double storey and wrap-around Kingston extensions
On the larger period houses towards Surbiton and New Malden, a wrap-around extension combines the side return with a rear projection to rework the whole ground floor, while a double storey build adds a bedroom or en-suite above. These schemes almost always need planning permission from Kingston Council and careful structural design, because new steel and foundations must work with existing walls that were never built to carry the extra load. We bring the engineer in from the start.
One team takes the project from foundations to final fit-out, so groundworks, steel, roofing, plastering, kitchen and decoration all follow one programme. We keep the disruption contained while you live in the house, protect the garden and access, and coordinate building control inspections at each key stage. The result ties into the original brickwork and rooflines of your Kingston home rather than looking bolted on, and it is signed off with the paperwork you will need later.
Kitchen extensions in Kingston upon Thames
63% of the houses in Kingston upon Thames are semi-detached or detached, which usually leaves room for a kitchen extension across the full rear width, with a steel beam over the opening into the house. The fit-out is priced on its own page, kitchen renovation in Kingston; the build figures are in the table above.
- Planning applications and permitted development assessments
- Single and double storey extensions
- First fix and second fix plumbing and electrics throughout
VOA Council Tax stock of properties, March 2025, for all 20 statistical areas in Kingston upon Thames. Counts rounded by the VOA.
The GS Renovation Difference in Kingston upon Thames
Homeowners across Kingston choose GS Renovation because we handle the extension end to end, from advising on permitted development versus planning through to the finished, decorated room. With our founder's 30+ years on the tools, we understand how Kingston's semis, terraces and period houses are built, install the steel the engineer sizes and deliver tidy work, signed off by building control, while you stay in the home.
- Weathertight shell reached before the fit-out begins
- Programme planned around party wall notice periods before excavation near a neighbour
- Photographs kept at each stage for your records
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George was brilliant. Lovely bloke, very reasonably priced and a perfectionist to boot. He completed our small kitchen renovation with care and great…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
FAQ
Frequently Asked Questions about House Extensions Kingston upon Thames
What is included in your house extensions price in Kingston upon Thames?
Every house extensions quotation for a Kingston upon Thames property lists the structural work, the following trades, the Kingston Council building control inspections and the making good, inside £2,000 to £2,800 per m² for a rear extension (indicative). Site protection and the daily clear-up at KT1 are included. The scope is written against what decides the job, because the width of the opening into the house decides the steel.
Does my Kingston extension need planning permission or is it permitted development?
Many single storey rear and side-return extensions in Kingston fall under permitted development, but if you want a side extension in a conservation area, your home has been extended before, or you want a double storey build, you will usually need planning permission from Kingston Council. We assess your specific house and handle whichever route applies, along with building regulations.
Does flood risk affect an extension in Kingston upon Thames?
It can, near the river. Parts of KT1 and KT2 sit within a flood risk area, which influences floor levels, floor finishes and where services such as boilers are placed. It is checked at the start, because the answer shapes the design and what Kingston Council will want to see. Building regulations still apply to the whole extension.
Does a side return extension in Kingston upon Thames need party wall notice?
Usually, because a side return trench hugs the boundary. Where your new footing will sit inside 3 metres of next door and bottom out lower than theirs, the Party Wall etc. Act 1996 asks for one month's warning in writing. A neighbour may simply sign their agreement; a dissent instead brings in surveyors, whose award fixes how the digging proceeds.
How is a glazed side return roof in Kingston upon Thames kept within regulations?
By balancing glass against insulation. Part L sets limits for new extensions, and a fully glazed roof can exceed them unless walls and floor are insulated better or the glazing performs well. Rooflights over the old wall line often bring in enough light with less glass. The steel carrying the roof is sized by the engineer.
What happens to the drain in the side passage when a Kingston upon Thames side return is filled in?
It usually ends up inside the extension. Rainwater and waste pipes often run down the side passage to a gully, so they are rerouted, with access chambers covered or moved. Part H sets the falls. If a public sewer runs there, the water company's consent comes before building control approves the plans.
Will a single storey extension in Kingston upon Thames pay the Community Infrastructure Levy?
Usually not. Kingston's CIL guidance says a domestic single storey extension of 30 square metres is not CIL liable because the extension is less than 100 square metres. The Kingston CIL came into force on 1 November 2015. The threshold matters on bigger schemes: a wrap-around ground floor with a first floor addition can pass 100 square metres, and then the liability is checked and the forms dealt with before the permission is implemented, not after.
Can a Kingston upon Thames extension application use the fast track service?
Kingston offers a fast track service for householder applications, for a fee, but it cannot fast track applications for listed buildings or properties in a conservation area. Check the address first. If the house is outside those designations and the drawings are ready, fast track can bring the start forward. Inside a conservation area the ordinary timetable applies, so we set the build start from the decision date and use the wait for the structural design and the party wall notices.
Which building control band does a Kingston upon Thames extension fall into?
Kingston has a standard charge for an above ground domestic extension greater than 10 m2 but not exceeding 40 m2, the same for full plans or building notice, with a higher charge for regularisation. A single storey rear extension within the SPD depth usually falls in that band unless it is very small. A scheme over 40 m2 falls outside it, so fix the floor area before asking for building control figures. Regularisation is for work done without approval, and it always costs more than applying first.
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